diff options
Diffstat (limited to 'fs/ext4/migrate.c')
| -rw-r--r-- | fs/ext4/migrate.c | 670 |
1 files changed, 670 insertions, 0 deletions
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c new file mode 100644 index 000000000..a19a96616 --- /dev/null +++ b/fs/ext4/migrate.c @@ -0,0 +1,670 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * Copyright IBM Corporation, 2007 + * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> + * + */ + +#include <linux/slab.h> +#include "ext4_jbd2.h" +#include "ext4_extents.h" + +/* + * The contiguous blocks details which can be + * represented by a single extent + */ +struct migrate_struct { + ext4_lblk_t first_block, last_block, curr_block; + ext4_fsblk_t first_pblock, last_pblock; +}; + +static int finish_range(handle_t *handle, struct inode *inode, + struct migrate_struct *lb) + +{ + int retval = 0, needed; + struct ext4_extent newext; + struct ext4_ext_path *path; + if (lb->first_pblock == 0) + return 0; + + /* Add the extent to temp inode*/ + newext.ee_block = cpu_to_le32(lb->first_block); + newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1); + ext4_ext_store_pblock(&newext, lb->first_pblock); + /* Locking only for convenience since we are operating on temp inode */ + down_write(&EXT4_I(inode)->i_data_sem); + path = ext4_find_extent(inode, lb->first_block, NULL, 0); + if (IS_ERR(path)) { + retval = PTR_ERR(path); + path = NULL; + goto err_out; + } + + /* + * Calculate the credit needed to inserting this extent + * Since we are doing this in loop we may accumulate extra + * credit. But below we try to not accumulate too much + * of them by restarting the journal. + */ + needed = ext4_ext_calc_credits_for_single_extent(inode, + lb->last_block - lb->first_block + 1, path); + + retval = ext4_datasem_ensure_credits(handle, inode, needed, needed, 0); + if (retval < 0) + goto err_out; + retval = ext4_ext_insert_extent(handle, inode, &path, &newext, 0); +err_out: + up_write((&EXT4_I(inode)->i_data_sem)); + ext4_free_ext_path(path); + lb->first_pblock = 0; + return retval; +} + +static int update_extent_range(handle_t *handle, struct inode *inode, + ext4_fsblk_t pblock, struct migrate_struct *lb) +{ + int retval; + /* + * See if we can add on to the existing range (if it exists) + */ + if (lb->first_pblock && + (lb->last_pblock+1 == pblock) && + (lb->last_block+1 == lb->curr_block)) { + lb->last_pblock = pblock; + lb->last_block = lb->curr_block; + lb->curr_block++; + return 0; + } + /* + * Start a new range. + */ + retval = finish_range(handle, inode, lb); + lb->first_pblock = lb->last_pblock = pblock; + lb->first_block = lb->last_block = lb->curr_block; + lb->curr_block++; + return retval; +} + +static int update_ind_extent_range(handle_t *handle, struct inode *inode, + ext4_fsblk_t pblock, + struct migrate_struct *lb) +{ + struct buffer_head *bh; + __le32 *i_data; + int i, retval = 0; + unsigned long max_entries = inode->i_sb->s_blocksize >> 2; + + bh = ext4_sb_bread(inode->i_sb, pblock, 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + i_data = (__le32 *)bh->b_data; + for (i = 0; i < max_entries; i++) { + if (i_data[i]) { + retval = update_extent_range(handle, inode, + le32_to_cpu(i_data[i]), lb); + if (retval) + break; + } else { + lb->curr_block++; + } + } + put_bh(bh); + return retval; + +} + +static int update_dind_extent_range(handle_t *handle, struct inode *inode, + ext4_fsblk_t pblock, + struct migrate_struct *lb) +{ + struct buffer_head *bh; + __le32 *i_data; + int i, retval = 0; + unsigned long max_entries = inode->i_sb->s_blocksize >> 2; + + bh = ext4_sb_bread(inode->i_sb, pblock, 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + i_data = (__le32 *)bh->b_data; + for (i = 0; i < max_entries; i++) { + if (i_data[i]) { + retval = update_ind_extent_range(handle, inode, + le32_to_cpu(i_data[i]), lb); + if (retval) + break; + } else { + /* Only update the file block number */ + lb->curr_block += max_entries; + } + } + put_bh(bh); + return retval; + +} + +static int update_tind_extent_range(handle_t *handle, struct inode *inode, + ext4_fsblk_t pblock, + struct migrate_struct *lb) +{ + struct buffer_head *bh; + __le32 *i_data; + int i, retval = 0; + unsigned long max_entries = inode->i_sb->s_blocksize >> 2; + + bh = ext4_sb_bread(inode->i_sb, pblock, 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + i_data = (__le32 *)bh->b_data; + for (i = 0; i < max_entries; i++) { + if (i_data[i]) { + retval = update_dind_extent_range(handle, inode, + le32_to_cpu(i_data[i]), lb); + if (retval) + break; + } else { + /* Only update the file block number */ + lb->curr_block += max_entries * max_entries; + } + } + put_bh(bh); + return retval; + +} + +static int free_dind_blocks(handle_t *handle, + struct inode *inode, __le32 i_data) +{ + int i; + __le32 *tmp_idata; + struct buffer_head *bh; + struct super_block *sb = inode->i_sb; + unsigned long max_entries = inode->i_sb->s_blocksize >> 2; + int err; + + bh = ext4_sb_bread(sb, le32_to_cpu(i_data), 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + tmp_idata = (__le32 *)bh->b_data; + for (i = 0; i < max_entries; i++) { + if (tmp_idata[i]) { + err = ext4_journal_ensure_credits(handle, + EXT4_RESERVE_TRANS_BLOCKS, + ext4_free_metadata_revoke_credits(sb, 1)); + if (err < 0) { + put_bh(bh); + return err; + } + ext4_free_blocks(handle, inode, NULL, + le32_to_cpu(tmp_idata[i]), 1, + EXT4_FREE_BLOCKS_METADATA | + EXT4_FREE_BLOCKS_FORGET); + } + } + put_bh(bh); + err = ext4_journal_ensure_credits(handle, EXT4_RESERVE_TRANS_BLOCKS, + ext4_free_metadata_revoke_credits(sb, 1)); + if (err < 0) + return err; + ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1, + EXT4_FREE_BLOCKS_METADATA | + EXT4_FREE_BLOCKS_FORGET); + return 0; +} + +static int free_tind_blocks(handle_t *handle, + struct inode *inode, __le32 i_data) +{ + int i, retval = 0; + __le32 *tmp_idata; + struct buffer_head *bh; + unsigned long max_entries = inode->i_sb->s_blocksize >> 2; + + bh = ext4_sb_bread(inode->i_sb, le32_to_cpu(i_data), 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + tmp_idata = (__le32 *)bh->b_data; + for (i = 0; i < max_entries; i++) { + if (tmp_idata[i]) { + retval = free_dind_blocks(handle, + inode, tmp_idata[i]); + if (retval) { + put_bh(bh); + return retval; + } + } + } + put_bh(bh); + retval = ext4_journal_ensure_credits(handle, EXT4_RESERVE_TRANS_BLOCKS, + ext4_free_metadata_revoke_credits(inode->i_sb, 1)); + if (retval < 0) + return retval; + ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1, + EXT4_FREE_BLOCKS_METADATA | + EXT4_FREE_BLOCKS_FORGET); + return 0; +} + +static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data) +{ + int retval; + + /* ei->i_data[EXT4_IND_BLOCK] */ + if (i_data[0]) { + retval = ext4_journal_ensure_credits(handle, + EXT4_RESERVE_TRANS_BLOCKS, + ext4_free_metadata_revoke_credits(inode->i_sb, 1)); + if (retval < 0) + return retval; + ext4_free_blocks(handle, inode, NULL, + le32_to_cpu(i_data[0]), 1, + EXT4_FREE_BLOCKS_METADATA | + EXT4_FREE_BLOCKS_FORGET); + } + + /* ei->i_data[EXT4_DIND_BLOCK] */ + if (i_data[1]) { + retval = free_dind_blocks(handle, inode, i_data[1]); + if (retval) + return retval; + } + + /* ei->i_data[EXT4_TIND_BLOCK] */ + if (i_data[2]) { + retval = free_tind_blocks(handle, inode, i_data[2]); + if (retval) + return retval; + } + return 0; +} + +static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode, + struct inode *tmp_inode) +{ + int retval, retval2 = 0; + __le32 i_data[3]; + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode); + + /* + * One credit accounted for writing the + * i_data field of the original inode + */ + retval = ext4_journal_ensure_credits(handle, 1, 0); + if (retval < 0) + goto err_out; + + i_data[0] = ei->i_data[EXT4_IND_BLOCK]; + i_data[1] = ei->i_data[EXT4_DIND_BLOCK]; + i_data[2] = ei->i_data[EXT4_TIND_BLOCK]; + + down_write(&EXT4_I(inode)->i_data_sem); + /* + * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation + * happened after we started the migrate. We need to + * fail the migrate + */ + if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) { + retval = -EAGAIN; + up_write(&EXT4_I(inode)->i_data_sem); + goto err_out; + } else + ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE); + /* + * We have the extent map build with the tmp inode. + * Now copy the i_data across + */ + ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS); + memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data)); + + /* + * Update i_blocks with the new blocks that got + * allocated while adding extents for extent index + * blocks. + * + * While converting to extents we need not + * update the original inode i_blocks for extent blocks + * via quota APIs. The quota update happened via tmp_inode already. + */ + spin_lock(&inode->i_lock); + inode->i_blocks += tmp_inode->i_blocks; + spin_unlock(&inode->i_lock); + up_write(&EXT4_I(inode)->i_data_sem); + + /* + * We mark the inode dirty after, because we decrement the + * i_blocks when freeing the indirect meta-data blocks + */ + retval = free_ind_block(handle, inode, i_data); + retval2 = ext4_mark_inode_dirty(handle, inode); + if (unlikely(retval2 && !retval)) + retval = retval2; + +err_out: + return retval; +} + +static int free_ext_idx(handle_t *handle, struct inode *inode, + struct ext4_extent_idx *ix) +{ + int i, retval = 0; + ext4_fsblk_t block; + struct buffer_head *bh; + struct ext4_extent_header *eh; + + block = ext4_idx_pblock(ix); + bh = ext4_sb_bread(inode->i_sb, block, 0); + if (IS_ERR(bh)) + return PTR_ERR(bh); + + eh = (struct ext4_extent_header *)bh->b_data; + if (eh->eh_depth != 0) { + ix = EXT_FIRST_INDEX(eh); + for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) { + retval = free_ext_idx(handle, inode, ix); + if (retval) { + put_bh(bh); + return retval; + } + } + } + put_bh(bh); + retval = ext4_journal_ensure_credits(handle, EXT4_RESERVE_TRANS_BLOCKS, + ext4_free_metadata_revoke_credits(inode->i_sb, 1)); + if (retval < 0) + return retval; + ext4_free_blocks(handle, inode, NULL, block, 1, + EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); + return 0; +} + +/* + * Free the extent meta data blocks only + */ +static int free_ext_block(handle_t *handle, struct inode *inode) +{ + int i, retval = 0; + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data; + struct ext4_extent_idx *ix; + if (eh->eh_depth == 0) + /* + * No extra blocks allocated for extent meta data + */ + return 0; + ix = EXT_FIRST_INDEX(eh); + for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) { + retval = free_ext_idx(handle, inode, ix); + if (retval) + return retval; + } + return retval; +} + +int ext4_ext_migrate(struct inode *inode) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + handle_t *handle; + int retval = 0, i; + __le32 *i_data; + struct ext4_inode_info *ei; + struct inode *tmp_inode = NULL; + struct migrate_struct lb; + unsigned long max_entries; + __u32 goal, tmp_csum_seed; + uid_t owner[2]; + + /* + * If the filesystem does not support extents, or the inode + * already is extent-based, error out. + */ + if (!ext4_has_feature_extents(inode->i_sb) || + ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) || + ext4_has_inline_data(inode)) + return -EINVAL; + + if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0) + /* + * don't migrate fast symlink + */ + return retval; + + percpu_down_write(&sbi->s_writepages_rwsem); + + /* + * Worst case we can touch the allocation bitmaps and a block + * group descriptor block. We do need to worry about + * credits for modifying the quota inode. + */ + handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, + 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb)); + + if (IS_ERR(handle)) { + retval = PTR_ERR(handle); + goto out_unlock; + } + goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) * + EXT4_INODES_PER_GROUP(inode->i_sb)) + 1; + owner[0] = i_uid_read(inode); + owner[1] = i_gid_read(inode); + tmp_inode = ext4_new_inode(handle, d_inode(inode->i_sb->s_root), + S_IFREG, NULL, goal, owner, 0); + if (IS_ERR(tmp_inode)) { + retval = PTR_ERR(tmp_inode); + ext4_journal_stop(handle); + goto out_unlock; + } + /* + * Use the correct seed for checksum (i.e. the seed from 'inode'). This + * is so that the metadata blocks will have the correct checksum after + * the migration. + */ + ei = EXT4_I(inode); + tmp_csum_seed = EXT4_I(tmp_inode)->i_csum_seed; + EXT4_I(tmp_inode)->i_csum_seed = ei->i_csum_seed; + i_size_write(tmp_inode, i_size_read(inode)); + /* + * Set the i_nlink to zero so it will be deleted later + * when we drop inode reference. + */ + clear_nlink(tmp_inode); + + ext4_ext_tree_init(handle, tmp_inode); + ext4_journal_stop(handle); + + /* + * start with one credit accounted for + * superblock modification. + * + * For the tmp_inode we already have committed the + * transaction that created the inode. Later as and + * when we add extents we extent the journal + */ + /* + * Even though we take i_rwsem we can still cause block + * allocation via mmap write to holes. If we have allocated + * new blocks we fail migrate. New block allocation will + * clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated + * with i_data_sem held to prevent racing with block + * allocation. + */ + down_read(&EXT4_I(inode)->i_data_sem); + ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE); + up_read((&EXT4_I(inode)->i_data_sem)); + + handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1); + if (IS_ERR(handle)) { + retval = PTR_ERR(handle); + goto out_tmp_inode; + } + + i_data = ei->i_data; + memset(&lb, 0, sizeof(lb)); + + /* 32 bit block address 4 bytes */ + max_entries = inode->i_sb->s_blocksize >> 2; + for (i = 0; i < EXT4_NDIR_BLOCKS; i++) { + if (i_data[i]) { + retval = update_extent_range(handle, tmp_inode, + le32_to_cpu(i_data[i]), &lb); + if (retval) + goto err_out; + } else + lb.curr_block++; + } + if (i_data[EXT4_IND_BLOCK]) { + retval = update_ind_extent_range(handle, tmp_inode, + le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb); + if (retval) + goto err_out; + } else + lb.curr_block += max_entries; + if (i_data[EXT4_DIND_BLOCK]) { + retval = update_dind_extent_range(handle, tmp_inode, + le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb); + if (retval) + goto err_out; + } else + lb.curr_block += max_entries * max_entries; + if (i_data[EXT4_TIND_BLOCK]) { + retval = update_tind_extent_range(handle, tmp_inode, + le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &lb); + if (retval) + goto err_out; + } + /* + * Build the last extent + */ + retval = finish_range(handle, tmp_inode, &lb); +err_out: + if (retval) + /* + * Failure case delete the extent information with the + * tmp_inode + */ + free_ext_block(handle, tmp_inode); + else { + retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode); + if (retval) + /* + * if we fail to swap inode data free the extent + * details of the tmp inode + */ + free_ext_block(handle, tmp_inode); + } + + /* We mark the tmp_inode dirty via ext4_ext_tree_init. */ + retval = ext4_journal_ensure_credits(handle, 1, 0); + if (retval < 0) + goto out_stop; + /* + * Mark the tmp_inode as of size zero + */ + i_size_write(tmp_inode, 0); + + /* + * set the i_blocks count to zero + * so that the ext4_evict_inode() does the + * right job + * + * We don't need to take the i_lock because + * the inode is not visible to user space. + */ + tmp_inode->i_blocks = 0; + EXT4_I(tmp_inode)->i_csum_seed = tmp_csum_seed; + + /* Reset the extent details */ + ext4_ext_tree_init(handle, tmp_inode); +out_stop: + ext4_journal_stop(handle); +out_tmp_inode: + unlock_new_inode(tmp_inode); + iput(tmp_inode); +out_unlock: + percpu_up_write(&sbi->s_writepages_rwsem); + return retval; +} + +/* + * Migrate a simple extent-based inode to use the i_blocks[] array + */ +int ext4_ind_migrate(struct inode *inode) +{ + struct ext4_extent_header *eh; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct ext4_super_block *es = sbi->s_es; + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_extent *ex; + unsigned int i, len; + ext4_lblk_t start, end; + ext4_fsblk_t blk; + handle_t *handle; + int ret, ret2 = 0; + + if (!ext4_has_feature_extents(inode->i_sb) || + (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + return -EINVAL; + + if (ext4_has_feature_bigalloc(inode->i_sb)) + return -EOPNOTSUPP; + + /* + * In order to get correct extent info, force all delayed allocation + * blocks to be allocated, otherwise delayed allocation blocks may not + * be reflected and bypass the checks on extent header. + */ + if (test_opt(inode->i_sb, DELALLOC)) + ext4_alloc_da_blocks(inode); + + percpu_down_write(&sbi->s_writepages_rwsem); + + handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out_unlock; + } + + down_write(&EXT4_I(inode)->i_data_sem); + ret = ext4_ext_check_inode(inode); + if (ret) + goto errout; + + eh = ext_inode_hdr(inode); + ex = EXT_FIRST_EXTENT(eh); + if (ext4_blocks_count(es) > EXT4_MAX_BLOCK_FILE_PHYS || + eh->eh_depth != 0 || le16_to_cpu(eh->eh_entries) > 1) { + ret = -EOPNOTSUPP; + goto errout; + } + if (eh->eh_entries == 0) + blk = len = start = end = 0; + else { + len = le16_to_cpu(ex->ee_len); + blk = ext4_ext_pblock(ex); + start = le32_to_cpu(ex->ee_block); + end = start + len - 1; + if (end >= EXT4_NDIR_BLOCKS) { + ret = -EOPNOTSUPP; + goto errout; + } + } + + ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); + memset(ei->i_data, 0, sizeof(ei->i_data)); + for (i = start; i <= end; i++) + ei->i_data[i] = cpu_to_le32(blk++); + ret2 = ext4_mark_inode_dirty(handle, inode); + if (unlikely(ret2 && !ret)) + ret = ret2; +errout: + ext4_journal_stop(handle); + up_write(&EXT4_I(inode)->i_data_sem); +out_unlock: + percpu_up_write(&sbi->s_writepages_rwsem); + return ret; +} |